Package structures and methods for forming the same

Abstract

A packaging structure and a method of forming a packaging structure are provided. The packaging structure, such as an interposer, is formed by optionally bonding two carrier substrates together and simultaneously processing two carrier substrates. The processing includes forming a sacrificial layer over the carrier substrates. Openings are formed in the sacrificial layers and pillars are formed in the openings. Substrates are attached to the sacrificial layer. Redistribution lines may be formed on an opposing side of the substrates and vias may be formed to provide electrical contacts to the pillars. A debond process may be performed to separate the carrier substrates. Integrated circuit dies may be attached to one side of the redistribution lines and the sacrificial layer is removed.

What is claimed is: 
     
       1. A method comprising:
 forming a patterned sacrificial layer over a first substrate, the patterned sacrificial layer having openings formed therein, the patterned sacrificial layer having a first surface and a second surface opposite the first surface, the openings extending from the first surface to the second surface, the second surface facing the first substrate; 
 after forming the patterned sacrificial layer having the openings, forming conductive pillars in the openings of the patterned sacrificial layer, the conductive pillars having a first surface distal from the first substrate, the first surface of the conductive pillars being level with a surface of the patterned sacrificial layer; 
 after forming the conductive pillars, electrically coupling one or more integrated circuit dies to the conductive pillars; and 
 after electrically coupling the one or more integrated circuit dies to the conductive pillars, removing the patterned sacrificial layer, thereby exposing sidewalls of the conductive pillars. 
 
     
     
       2. The method of  claim 1 , wherein the first substrate comprises a first carrier substrate and a dielectric layer over the first carrier substrate. 
     
     
       3. The method of  claim 2 , wherein the first substrate further comprises a conductive layer, the dielectric layer being interposed between the conductive layer and the first carrier substrate. 
     
     
       4. The method of  claim 3 , wherein the conductive layer comprises a conductive foil. 
     
     
       5. The method of  claim 4 , wherein the conductive layer is attached to the dielectric layer by an adhesive. 
     
     
       6. The method of  claim 3 , wherein after forming the patterned sacrificial layer, the forming the conductive pillars comprises performing a electroplating process or electrochemical process to form a conductive material in the openings. 
     
     
       7. The method of  claim 6 , further comprising performing a planarization process to remove conductive material from an outer surface of the patterned sacrificial layer. 
     
     
       8. The method of  claim 1 ,
 wherein forming the patterned sacrificial layer over a first substrate comprises:
 forming a first layer over a first surface of the first substrate; 
 forming a second layer over the first layer; and 
 forming a first opening in the second layer; and 
 
 wherein forming conductive pillars in the openings comprises:
 after forming the second layer, forming a conductive element in the first opening; and 
 
 further comprising:
 attaching a second substrate to the second layer such that the second layer is interposed between the second substrate and the first substrate. 
 
 
     
     
       9. The method of  claim 1 , wherein forming the patterned sacrificial layer over the first substrate comprises forming the patterned sacrificial layer on a first carrier substrate, and further comprising:
 forming another patterned sacrificial layer on a second carrier substrate, the first carrier substrate being bonded to the second carrier substrate, the first carrier substrate and the second carrier substrate being interposed between the patterned sacrificial layer and the another patterned sacrificial layer; 
 attaching a first interposer substrate on the patterned sacrificial layer and a second interposer substrate on the another patterned sacrificial layer; 
 forming additional conductive pillars in openings of the another patterned sacrificial layer; 
 forming first through vias through the first interposer substrate to respective ones of the conductive pillars and second through vias through the second interposer substrate to respective ones of the additional conductive pillars; and 
 separating the first carrier substrate and the second carrier substrate. 
 
     
     
       10. A method comprising:
 forming a first layer over a first surface of a first substrate; 
 forming a second layer over the first layer; 
 forming a first opening in the second layer; 
 after forming the second layer, forming a conductive element in the first opening; 
 attaching a second substrate to the second layer such that the second layer is interposed between the second substrate and the first substrate; 
 after attaching the second substrate, forming an electrical connection through the second substrate to the conductive element; 
 electrically coupling one or more integrated circuit dies to the conductive element, the integrated circuit dies being coupled to a side of the second substrate opposite the conductive element; 
 removing the first substrate; and 
 removing the first layer and the second layer, thereby exposing sidewalls of the conductive element. 
 
     
     
       11. The method of  claim 10 , wherein the first layer comprises a dielectric layer. 
     
     
       12. The method of  claim 10 , wherein after forming the conductive element, an exposed surface of the second layer and an exposed surface of the conductive element are level. 
     
     
       13. The method of  claim 10 , wherein the second substrate comprises a laminated substrate. 
     
     
       14. The method of  claim 10 , wherein the second substrate comprises an Ajinimoto buildup film (ABF), glass, silicon oxide, aluminum oxide, or a combination thereof. 
     
     
       15. The method of  claim 10 , wherein forming the electrical connection comprises:
 after attaching the second substrate, forming a second opening through the second substrate; and 
 depositing a conductive material in the second opening. 
 
     
     
       16. A method comprising:
 forming a first sacrificial layer on a first carrier substrate and a second sacrificial layer on a second carrier substrate, the first carrier substrate being bonded to the second carrier substrate, the first carrier substrate and the second carrier substrate being interposed between the first sacrificial layer and the second sacrificial layer; 
 patterning the first sacrificial layer to form first openings and the second sacrificial layer to form second openings; 
 filling the first openings and the second openings with a conductive material, thereby forming first pillars and second pillars, respectively; 
 attaching a first interposer substrate on the first sacrificial layer and a second interposer substrate on the second sacrificial layer; 
 forming first through vias through the first interposer substrate to respective ones of the first pillars and second through vias through the second interposer substrate to respective ones of the second pillars; 
 separating the first carrier substrate and the second carrier substrate; and 
 after the separating, removing the first sacrificial layer to expose sidewalls of the first pillars. 
 
     
     
       17. The method of  claim 16 , prior to removing the first sacrificial layer, placing solder on the first pillars. 
     
     
       18. The method of  claim 16 , after removing the first sacrificial layer, placing solder on the first pillars. 
     
     
       19. The method of  claim 18 , wherein the solder extends along sidewalls of the first pillars. 
     
     
       20. The method of  claim 16 , wherein forming the first sacrificial layer on a first carrier substrate comprises:
 forming a dielectric layer over the first carrier substrate; and 
 forming a conductive layer over the dielectric layer, wherein the first sacrificial layer is formed over the conductive layer.